(1) It is a shock absorber to absorb the vehicle vibrations caused by the uneveness of the road, he hydraulic shock absorbers used in most cars. PA0 (2) In case of the hydraulic shock absorber, when a bump hits the wheel of a car the velocity of the fluid passing through the tiny holes of the will be very high creating a very high resistance in it. It will almost as a solid rod between the wheel and the frame eliminating the flexibility of the spring supporting the frame of the car. The friction shock absorber does not have this disadvantage. When the wheel moves up at a very high velocity the friction will not increase, on the contrary it will decrease. This means that the friction shock absorber will absorb the viobrations while keeping the flexibility of the spring.